It has been known for several years that certain saturated, mono- and di- unsaturated aldehydes of chain length between about 6 and about 20 carbon atoms, especially those having an even number of carbon atoms between 12 and 18, exhibit sex attractant properties for certain insects, in particular, Lepidoptera and certain beetles.
Generally speaking, it has been found that the mono unsaturated aldehydes wherein the double bond is in the Z or E orientation are specific attractants either per se or in combination with compounds of similar structure for a substantial number of a particular species. This property has been used in the ecologically sound approach of insect control by trapping or disorientation. The approach has become so well accepted that a number of these aldehydes are commercially available.
A sample list (though not exclusive) is set forth hereinbelow in Table I. Certain abbreviations will be employed hereinbelow, namely, the indication Z9, E11, -16:ALD (or ACF) indicates (Z,E)-9,11-hexadecadienal or (Z,E)-9,11-hexadecadienoyl fluoride respectively.
TABLE I ______________________________________ Commercially available Aldehyde pheromones and pest insects controlled.* Commercial attractant Common name Latin name or pheromone ______________________________________ Leptoptera Sugarcane (Diatraea saccharalis) Z9, E11-16: ALD borer Navel (Amylois transitella) Z11, Z13-16: ALD Orange worm Artichoke (Platyptilia carduidactyla) Z11-16: ALD Plume moth Cranberry (Crambus topiarius) Z13-18: ALD Girdler Pickleworm (Diaphania nitidalis) E11-16: ALD moth Rice Stein- (Chilo suppressalis)/ Z13-18: ALD borer/Cran- (Crambus topiarius) Z7-14: ALD berry Girdler Olive moth Spruce (Choristoneura fumiferana, E11-14: ALD budworms O. occidentalis) Z11-14: ALD Tobacco bud- (Heliothis virescens, Z11-16: ALD worm, cotton H. zea, Z9-16: ALD bollworm, etc. H. armigera, Z7-16: ALD H. phloxiphaga) Z9-14: ALD 16: ALD 14: ALD Coleoptera Boll weevil (Anthonomus grandis) 3,3-dimethyl-.DELTA.1,.alpha.- cyclohexane- acetaldehyde Grain and (Trogoderma granarium) E8-14-CH.sub.3 ; stored product T. inclusum, 16: ALD beetles T. glabrum Z8- 14-CH.sub.3, 16: ALD ______________________________________ *The notation Z9, E11-16: ALD indicates (Z,E)9,11-hexadecadienal.
A further listing of aldehydes and their attractant effects on certain insects, in particular but not limited to Lepidoptera will be found in the article by M. Inscoe in Kydonieus and Beroza, Insect Suppression with Controlled Release Pheromone Systems (CRC Press, Boca Raton, 1982), volume 2, at page.
The use of acyl fluorides of moderate chain length for any purpose has not heretofore been reported with one exception. German OLS No. 2108576 reports that certain moderate chain length highly branched mono-olefinic acyl fluorides are useful in insecticides at concentrations of 4.8 to 20 Kg/m.sup.3. This concentration is of course vastly greater than that necessary to bring about a sex attractant effect.
Methods of oxidizing aldehydes to the corresponding acids without interference with any unsaturation which may be present are of course well known in the art. Several methods have also been reported for the conversion of alkanoic and alkenoic acids to the corresponding acyl fluorides. The reaction of acyl chlorides with pyridinium polyhydrogen fluoride is reported by Olah et al., (J. Org, Chem., 44, 3872 (1979)). Another route which comprises treating the acid with potassium fluorosulfonate was reported by Seel and Langer (Chem. Ber., 91, 2553 (1958)). Yet another, though less convenient mode is that reported by Siddall in German OLS No. 2108576, in which the acid is converted into the corresponding acid chloride by means of thionyl chloride and the product subsequently fluorinated with hydrogen fluoride. Yet another method is disclosed by Olah, et al., which comprises reacting the appropriate acid with cyanuric fluoride in acetonitrile in the presence of pyridine. (Synthesis 4, 87 (1973).